On 6/23/2020 at 10:39 PM, CanadianHomeChef said:
I know the Vollrath mirage series is known for temperature accuracy. Not sure how they do it. We have a mirage cadet at my school in the foods room... never used it though.
i emailed vollrath about their 4-series temp control (when not using a probe), and this is what i learned:
they do sense cookware temperature and support closed-loop temp control in this manner when not using a probe. how does it work?
it seems there is a contact-based temp sensor below the glass, so it relies on heat being conducted from the cookware, through the glass, and into the sensor. this is a cookware-air-glass-sensor interface, so there's some appreciable thermal resistance. this is fairly reliable but not super accurate, and i was told compensation is not attempted in software. they even told me that if you want to shoot for 140°F pan temp, you might try choosing a setpoint of 150°F or something.
compared to the CF, this 4-series cookware temp sensing is inferior imo. first of all, the CF contact sensor is spring-loaded, ensuring solid contact with the cookware. also, the intermediate material in the thermal interface is metal instead of glass. these factors mean less thermal resistance, and therefore less temperature drop between the pan and the sensor. furthermore, in my testing, i've found the CF pan temp control to be pretty damn accurate, which surprised me, so i'm sure they're doing compensation in software on top of that. also, the time response will be faster -- temp change should be detected more quickly on the CF.
still, i would love to try a vollrath unit. the 'expanded field' feature is interesting. supposedly the cookware continues to be heated even when it's lifted a bit above the surface, giving it a more gas-like feel. not exactly a killer feature, because on the CF, cooking is paused for a moment until you set it back down on the surface. i'm not sure pausing heating for a moment while you flip something in the pan is a problem. but still, that's pretty cool if it works as advertised.
even though the MSRP on the 4-series is higher than the CF ($1650 vs $1500), it seems the 4-series can, in reality, be had for much cheaper than the CF:
https://chefstoys.com/40642/vollrath-mpi4-1800s-4-series-countertop-induction-range-1800-watts-40642
https://chefstoys.com/40643/vollrath-mpi4-1440s-4-series-countertop-medium-power-induction-range-w
it's about $875 on this site. so from a price perspective, the vollrath seems pretty attractive compared to the CF. also, it's interesting that the 1800W and 1440W models are the same price.
i don't think i'd like that touch interface slider on the 4-series though. real knobs are much more appealing to me.
so, in summary.. here's my take on the CF vs the 4-series:
- the CF costs almost twice as much as the 4-series
- they probably perform similarly in probe-control mode
- the CF comes with a superior probe clip (that awesome rubber ball thing)
- the CF's pan-control mode (contact-based cookware temp sensing) is almost certainly superior to the 4-series in both accuracy and speed
- the CF's UI is more capable with several soft buttons, knobs, and a graphical color LCD. this lets you display more info on the screen at once, like timers (count-up or count-down). the vollrath has only a simple numerical segment display, and i don't think it's possible to view both pan and probe temp simultaneously. the probe models have a touch-based temp slider (probably capacitive sensing), and the non-probe models have a knob instead; i wonder why?
- the vollrath lets you run it in "dumb mode" without temp feedback if you want. you can pick power output from 0-100% or something. unbelievably, the CF does not have such a feature! you can choose from three power output settings (slow, med, fast), but it is always bound by a temp setting. sometimes i just want to cook "classic style" and not think about temperatures, and frustratingly, the CF doesn't let you cook like that!!
- they both have a program mode, but it's not clear to me yet which is superior. imo, the CF's is not very useful, but you can program it without a PC, and the superior UI and display would in theory would allow for more possibilities.
- the 4-series has an "expanded field" which supposedly continues heating without interruption if you lift the pan a bit to sautée or flip something. on the CF, it pauses for a moment until you return the pan.
- unlike the CF, the 4-series is available in the US in 240V models at up to 3800W!
